Photographic developer containing a pyridinium salt and process of development



Patented Aug. 11, 1953 f mmfrss WENT .QFFI-CF 2,648,604 PHOTOGRAPHIC DEvELoPER CONTAINING A PYRIDINIUMP, SALT Qi MENT; P

AND PROCESS OF No Drawing. Application December 28, 1951, "Serial No: 263,981 I 18 Claims. 1

This invention relates to photographic defor photographic developers;"'

velopers, randf more particularly to accelerators In the 'devel'opme'nt'ofph tographic materials,

it is often des'ired to accelerate-the rate ofde- 2 vide black and white and color developers having an increased rate otdevelopment southat the,

development time is substantiallydecreased;

velopment' and to increase" the'effe'ctive -photographic speed of the developed materials. However, the"acceleratorsjknown'iso farto the art increase not only" the eifectiveii eniulsion speed, but also thecontrastof the "developed emulsion.

The latter characteristicfriarnely, the increased contrast is seldom desirable since'it afiects the visual appearance of'the pictureto the extent that the pleasingrrniddle tones and details in the shadow and high' ilightareas are'fre'quently Moreover,"many of the"lnown accelera*' lost. tors increase the pH; of the" developer solution,-

the accelerating action o'f'rnany of the knOwnac celerators is very largelydueto thincr'easedpI-I I 'quinone and the like, and provide greater 'efieoa feature: which'is flalway's "undesirable; Iii-fact, tive speed in the developed materialswithouti-any.

and the results, asundesirablea's theydnay-"be" at times, can be duplicated more'siniply and coo I nomically by adding more alkali," such "as'so dium carloonate to th'edeveloping solution.

It is also known that'various quateinaryammoniurn salts may be added to photographic" black and white and color developing solutionsg' For example, quaternary ammonium "salts of formers fast to diffusion, as disclosed in'United 2,292,575; 2,303,928 ahd-'2',307,399"withsan alkae line color developersolution"containingKaapria. J mary aromatic amine as the developinghagent benzothiazole or a'minobenzothiazole tend to "decrease graininess; pyridiniurnwalts'" "sulistituted by a 'n dial-nine a a o --the efiective increase in 'speed' is obtainedrwiths radical act as dev'e'lopingegents; surface"ac tive quaternary ammonium salts havin a 'long chain hydrocarbon radicalat'tached to the pentavalentnitrogen atom change the color of dye images obtained by color coupling development,

and surface active pyri diniu'rn salts substituted" iii by a hydrophilicigroup of increase eight'carbon atoms restrain development in'the shoulder density region. 111' other quaternary 0 ammonium salts disclosed and suggested, impart to the photographic developing solution graphic characteristics of the'developed photographic materials; However, theseotherwisede loss of maximum density,

It is, therefore, an objectof the present invention to provide lolackand white and color developers having an increased rate of development so thata greater efiective speed is iniparted to the developed photographic" material e "'alkoxy-substituted pyridinium nucleusfe. g.,z 'a=-u.

five carbon atoms attached to the pentavalent,

"can be reduced to less than'haltby ithe a'dditio w-useful life of developing solutions, especially when used as constituents of: both: properties which cause a change in"the"'photo-" d t p her Solution? ance with "the I present inventiomare "represented 'ing agent, a quaternarypyridinium .salt having a short chain aliphaticradical of. not. more than -concurrent increase in contrasts It haszialso been found that in developing color images -multi-co1or photographic layers containing-color -States Patents 2,178,61 2 2,179,228; '.-2,17.-9;234; 2,179,238-9; 2,179,244; 2,186,719; J2,'186,851-.-2;; 2,186,732-4; 2,186,8l9; 2,200,306} 1 2,280,722;

and a pyridinium salt having a sh'ort chain alkyl a substituent on the pentavalent nitrogenitatom;

out any change in contrast; irll oftheflayersiare developed simultaneously and the images" formed are of excellent qualitys" COII'ESDOIldilIglYflIWhGH no increase in speed is desired; the 'developing time with black and White and 'color 'develop'ers of a pyridinium sa'lttothedeveloperl; Another valuable characteristic 'property of the pyridinium salts is their abilityto prolongther the developer jby the following general formula:

'plete an unsubstituted pyridinium *nucleus, "an":

3-ethoxy-, 2,4-dimethoxy-, 2,4-diethoxy-, 2,5-diethoxy-, or 3,5-diethoxy-pyridinium nucleus; a picolinium nucleus, e. g., a 4-methyl-, 2-methyl-, or B-methyl-pyridinium nucleus; a lutidinium nucleus, e. g., a 2,3dimethyl-, 2A-dimethyl-, 2,5- dimethyl-, 2,6dimethyl, 3,4-dimethyl-, 3,5-dimethyl-, 2-ethyl-, 3-ethylor 4-ethyl-pyridinium nucleus; a collidinium nucleus, e. g., a 2-propyl-, 2-isopropyl-, 4-methyl-2-ethyl-, -methyl- 3-ethyl-, 2-methyl-4-ethyl-, 2-methy1-5-ethyl-, 2-methyl-6-ethyl-, 2,3,4-trimethyl-, or 2,3,6- trimethyl-pyridinium nucleus, or a parvolinium nucleus, e. g., a 2-butyl-, 2-isobutyl-, 3,5 dimethyl 2 ethyl, 2,6 dimethyl-3-ethyl-, 2,6 dimethyl-4-ethyl-, 2,4 diethylor 3,4-diethyl-pyridinium nucleus; wherein R is a short chain aliphatic radical having not more than 5 carbon atoms, such as alkyl, e. g., methyl, ethyl, propyl, butyl or amyl; chloroor bromoalkyl, e. g., fl-chloroethyl, fi-bromoethyl, -chloropropyl or 'y-bromopropyl; hydroxyalkyl, e. g., b-hydroxyethyl, fi-hydroxypropyl, or fi,' dihydroxypropyl, carboxymethyl; carbalkoxymethyl, e. g., carbomethoxymethyl, carbethoxymethyl or carbopropoxymethyl, carbcxamidomethyl; N-substituted carboxamidomethyl, e. g., N,N-dimethylcarboxamidomethyl; alkoxyalkyl, e. g., methoxymethyl, ethoxymethyl, ethoxyethel or propoxymethyl; and wherein X represents an anion selected from the group consisting of chloride, bromide thiocyanate, methosulfate and thiocyanate.

The following is merely a suggestive listing of pyridinium salts which may be employed for the purpose herein set forth:

l-methylpyridinium chloride. l-ethylpyridinium bromide. 1- (,B-chlorethyl) pyridinium chloride. 1-(1-5-bromethyl) pyridinium bromide. l-propylpyridinium bromide. l- (B-hydroxyethyl) pyridinium chloride. 1-methoxymethylpyridinium bromide. l-ethoxymethylpyridinium bromide. 1propoxymethylpyridinium bromide. 1- (,B-acetoxyethyl) pyridinium chloride. 1- (fly-dihydrosrypropyl) pyridinium chloride. 1-carboxymethylpyridinium chloride. 1-carboxymethylpyridinium bromide. 1-carbomethoxymethylpyridinium bromide. 1-carbethoxymethylpyridinium chloride. 1-methyl-2-methylpyridinium chloride. 1-methyl-2-methylpyridinium bromide. 1-methyl-3-methylpyridinium bromide. 1-methyl-methylpyridinium bromide. 1-ethyl-2 methylpyridinium bromide. 1-ethyl-4-methylpyridinium bromide. 1-carboxymethyl-2-methoxypyridinium bromide. l-carboxymethyl-S-methylpyridinium chloride. 1-carboxymethyl-2-methylpyridinium chloride. 1-carboXymethyl-Z-methylpyridinium thiocyanate. 1-carbethoxymethyl-3-picolinium chloride. 1-methyl-3-ethylpyridinium chloride. 1-carboXymethyl-3-ethylpyridinium chloride. l-(fi hydroxyethyl) 2 methylpyridinium bromide. 1,2,3-trimethylpyridinium methosulfate. 1,2,4-trimethylpyridinium methosulfate. 1,2,5-trimethylpyridinium methosulfate. 1,2,6-trimethylpyridinium methosulfate. 1,3,5-trimethylpyridinium methosulfate. 1-ethyl-2,3-dimethylpyridinium ethosulfate. 1-ethyl-2,4-dimethylpyridinium ethosulfate. 1ethyl-2,5-dimethylpyridinium ethosulfate. 1-ethyl-2,6-dimethylpyridinium ethosulfate.

4 1-ethyl-3,5-dimethylpyridinium ethosulfate. 1-methyl-2-propylpyridinium chloride. 1-methyl-2-isopropylpyridinium bromide. l-hydroxyethyl 2 methyl 5 ethylpyridinium chloride. 1,5-diethyl-2-methylpyridinium bromide. 1,4-dimethyl-3-ethylpyridinium bromide. 1,2,4,6-tetramethylpyridinium bromide. 1-methyl-2-methoxypyridinium methosulfate. 1-ethyl-3-methoxypyridinium ethosulfate. 1-ethyl-3-methoxypyridinium bromide. 1-carboxymethyl-2-ethoxypyridinium chloride. l-carbethoxymethyl 2 ethoxypyridinium chloride. l-methyl 2,4 dimethoxypyridinium methosulfate.. 1-acetamido-2,4-diethoxypyridinium chloride. 1-ethyl-2,5-diethoxypyridinium ethosulfate. 1 carbethoxymethyl 3,5 diethoxypyridinium chloride.

The foregoing quaternary pyridinium salts in which the nitrogen atom occupies the 1-position are prepared by reacting pyridine or a substituted pyridine, e. g., a picoline, a lutidine, a collidine, a parvoline or an alkoxypyridine with a quaternizing agent, e. g., an alkyl chloride, alkyl bromide, dimethyl sulfate, diethyl sulfate, chloroacetic acid, methyl chloroacetate, ethyl chloroacetate, chloroacetamide and the like. The quaternization may be carried out by heating or at room temperature in the presence of suitable solvent diluents, such as ether, benzene, toluene, xylene and the like, or under pressure at elevated temperatures depending on the relative reactivity of the ingredients. The chlorides and bromides may also be obtained by first preparing the corresponding iodide and subsequently converting it by the use of the appropriate silver halide. The thiocyanates are prepared by the addition of alkali thiocyanate to the solution of a more soluble quaternary salt.

The quaternary pyridinium salts are readily soluble in water and in alkaline solutions and can be used in concentrations varying from 0.3 gram per liter to the limit of their solubility in alkaline developer solutions. However, it has been found that for practical results, concentrations ranging from 0.5 gram to 7 grams per liter of developer solution are the most useful.

The following examples will illustrate developing solutions containing such quaternary pyridinium salts.

Example I Grams p-Monomethylaminophenol sulfat 1.5 Hydroquinone 3.0 Sodium sulfite (anhydrous) 45.0 Sodium carbonate (monohydrate) 6.0 Potassium bromide 0.8 1-ethyl-Z-methylpyridinium chloride 0.5 Water to make 1 liter This tank developer gives, on 6 to 8 minutes development of a roll film at 20 C. followed by Washing and fixing, a negative having an ASA speed rating of about 96. Increasing the concentration of the 1-ethyl-Z-methylpyridinium salt to 5.0 grams per liter of developer solution produced a negative having an ASA speed rating of 128. The omission of the l-ethyl-2-methylpyridinium chloride from the developer solution leads, under otherwise identical conditions, to a negative having an ASA speed rating of only 64.

ExampZerI-I The useful life of the developers containing the 1-ethyl-2-methylpyridinium' salt could be lengthened to the extent that'it ermitted the development of rolls' of i exposed film without showing any'speed loss' or-cha-n'ge-of: gradation by thegradual addition of a replenisherhaving the following composition:

-Grams p.-Monomethylaminophenolsulfate. 3.0;- I-I ydroqui'noner 6.0 Sodium sulfite 45=0- Sodium carbonate (monohydrate) 12.0 1-ethyl-2-methylpyridmium: ch1or-ide. 5.0:

Water to make 1 liter Grams p-Monomethylaminophenol sulfate 0.8 I-Iydroquinone 1.2 Sodium sulfite (anhydrous) 45.0 Potassium metabisulfite' 4L0. Sodium carbonate. (monohydrate) Water to make 1 liter The addition. of. 5 grams of l-(fi-hydrcxyethyl) pyridinium. chloride to this. solution. accel' rated the developing rate. and increased. the effective photographic speed of a developedroll filmby 100% whencompared with. the speed of a similar roll. film processed. in. a. developer containing. no pyridinium. salt.

Example IV Grams N-ethyl-N-c-hydroxyethyl p phenylenediamine sulfate 637. Sodium hexametaphosphate' 1.0 Sodium bisulfite 2.0"

Sodium carbonate 10.0..0. I-Iydroxylamine. hydrochloride 1.0- Potassium bromide 1.0. Water to. make 1 liter This color developer was. usedf'or the develop ment': of an exposed color negative film at ateinperature of 20 C. After developing for 20- minutes, a negative having an ASA speedrating of 10 was obtained: By adding 2 grantee? 1,2 dimethylpyridinium methosulfate to the same-developer solution, an image was developed in'a similar'color film which has anAS A speed rating of 18 without noticeably changing the grada' honor. the balance of the'd'eveloped picture. The color photographic multilayer elementused in the foregoing example consists of an integral tripack. emulsion coated on a clear cellulose acetate or nitrate film base. Each of the emulsion layers is sensitized to one of the primary colors of light, namely, blue, green and. red. The top la'yer is blue sensitive, the middle layer is green sensitive, and-the bottom layeris red sensitive. The green sensitive and blue sensitive emulsion layers are separatedby a yelloiv,.,blu.e absorbing filter layer. Each of the three silver halidewemulsion: layers. contains :dye.for-ming.com-

pounds: which unite during the development of; the. silver image in a. primary aromatic. amino" developing; agentto form a dyewith' the 'oxida tionzprodu'ct. of thedeveloping agent. A-.ye1lowdye is formed in the blue sensitive emulsion layer, a magenta dye is formed in the green sensitive emulsion, and a cyan dye is formed in the red sensitive emulsion. The combination of the dye images from these printing primaries yields the color. picture after the removalof the developed silver by bleaching, followed by fixing. Suitable:

methods forthe preparation: of multi-color'emuL- sion layers have been described in the literature.

relating to:color'photography and are, therefore; not described here.

Example V Gramsp-Amincr-di:(p-hydroxyethyl) aniline sulfate: 6.0 Sodium. hexametasulfate 1.0 Sodium bisulfite 2.0

Sodiumtcarbonate (monohydrate) 100.0 Hydroxylamine hydrochloride Potassium. bromide' Water to make 1 liter A color paper, similar in. construction tothe. color filmdescribed in.- Example. IV withthe.

exception that the three. emulsions were coated on a: paper base, was developed. for. 20 minutes at 20 C.. in the abovedeveloper. By the: addition of 3.0 grams or l-carboxymethyl--2-methyl-- pyridinium bromide to a similar developer, the increase. in the" efiective photographic: speed of the developed material: was by afactor" oi 2,

without a. noticeable change of contrast or loss;

of color balance.-

Example. VI

A color. positive filmcoatedon a. white opaque base but. otherwise similar. in construction to the negativefilm. used inExample. IV, was exposedthrough a. color transparency and. developed for 18. minutes at. a temperature of. 20 CL in a, dc.- veloper. having the following, composition 2..

Grams 4-diethylami'noaniline hydrochloride 6.0 Sodium hexametasulfate 1.0 Sodium bisulfite 2.0

Sodium carbonate 100.0 Hydroxylamine hydrochloride 1.0 Water. to. make 1. liter By adding'Z'LO grams ofjl-(carbethoxymethyl') 2.-methyl'pyridinium thiocyanate,. the-increase. in

the effective photographic-speed oi'the. developed.

color material wasby. 50%. without. any increase of contrast or loss oi color. balance. By in.-

creasing the amount of added pyr-idi-niumv salt.

to 610 grams,.itis possible to increase the effective photographic. speed of the developed cpaquematerial; by without noticeable change in contrast. Concentrations. of. over 7.0 grams. per. liter tend to destroy the color balance.

The. above examples. are to be. regarded as.

We claim:

1. An alkaline photographic developer for silver halide emulsions comprising an aromatic silver halide developing agent and a pyridinium salt selected from the class consisting of those corresponding to the following general formula:

wherein P represents the atoms necessary to complete a heterocyclic ring structure selected from the class consisting of pyridinium, picolinium, lutidinium, collidinium, parvolinium and alkoxy-substituted pyridinium radicals, R represents an aliphatic radical of not more than carbon atoms, said radical selected from the group consisting of alkyl, chloroalkyl, bromoalkyl, hydroxyalkyl, carboxymethyl, carbalkoxymethyl and alkoxyalkyl, and X is an anion selected from the class consisting of chloride, bromide, thiocyanate, methosulfate and ethosulfate.

2. An alkaline photographic developer for a silver halide emulsion comprising an aromatic silver halide developing agent and 1-ethyl-2- methylpyridinium chloride.

3. An alkaline photographic developer for a silver halide emulsion comprising an aromatic silver halide developing agent and l-(fl-hydroxyethyl) pyridinium chloride.

4. An alkaline photographic developer for a silver halide emulsion comprising an aromatic silver halide developing agent and 1,2-dimethylpyridinium methosulfate.

5. An alkaline photographic developer for a silver halide emulsion comprising an aromatic silver halide developing agent and l-carboxymethyl-2-methylpyridinium bromide.

6. An alkaline photographic developer for a silver halide emulsion comprising an aromatic silver halide developing agent and 1- (carbethoxymethyl) -2-methylpyridinium thiocyanate.

'7. In the development of a photographic image, the step comprising the development of an exposed silver halide emulsion in an alkaline developer containing an aromatic silver halide developing agent for said emulsion and a developing accelerator selected from the class consisting of those having the following formula:

wherein P represents the atoms necessary to complete a heterocyclic ring structure selected from the class consisting of pyridinium, picolinium, lutidinium, collidinium, parvolinium and. alkoXy-substituted pyridinium radicals, R represents an aliphatic radical of not more than5 carbon atoms, said radical selected from the group consisting of alkyl, chloroalkyl, bromoalkyl, hydroxyalkyl, carboxymethyl, carbalkoxymethyl and alkoxyalkyl, and X is an anion selected from the class consisting of chloride, bromide, thiocyanate, methosulfate and ethosulfate.

8. In the development of a photographic image, the step comprising the development of an exposed silver halide emulsion in an alkaline developer containing an aromatic silver halide developing agent for said emulsion and 1-ethyl-2- methylpyridinium chloride.

9. In the development of a photographic image, the step comprising the development of an ex- 8 posed silver halide emulsion in an alkaline developer containing an aromatic silver halide developing agent for said emulsion and 1(;3-hydroxyethyhpyridinium chloride.

10. In the development of a photographic image, the step comprising the development of an exposed silver halide emulsion in an alkaline developer containing an aromatic silver halide developing agent for said emulsion and 1,2-dimethylpyridinium methosulfate.

11. In the development of a photographic image, the step comprising the development of an exposed silver halide emulsion in an alkaline developer containing an aromatic silver halide developing agent for said emulsion and l-carboxymethyl-2-methylpyridinium bromide.

12. In the development of a photographic image, the step comprising the development of an exposed silver halide emulsion in an alkaline developer containing an aromatic silver halide developing agent for said emulsion and l-(carbethoxymethyl) 2 methylpyridinium thiocyanate.

13. A color forming photographic developer comprising a primary amino silver halide developing agent and a pyridinium salt selected from the class consisting of those having the following formula:

wherein P represents the atoms necessary to complete a heterocyclic ring structure selected from the class consisting of pyridinium, picolinium, lutidinium, collidinium, parvolinium and alkoxy-substituted pyridinium radicals, R represents an aliphatic radical of not more than 5 carbon atoms, said radical selected from the group consisting of alkyl, chloroalkyl, brornoalkyl, hydroxyalkyl, carboxymethyl, carbalkoxymethyl and alkoxyalkyl, and Xis an anion selected from the class consisting of chloride, bromide, thiocyanate, methosulfate and ethosulfate.

14. color forming photographic developer comprising a primary aromatic amino silver halide developing agent and l-ethyl-2-methylpyridinium chloride.

15. color forming photographic developer comprlsing a primary aromatic amino silver halide developing agent and l-(B-hydroxyethyl) pyridinium chloride.

16. color forming photographic developer comprising a primary aromatic amino silver halide developing agent and 1,2-dimethylpyridinium methosulfate.

17. A color forming photographic developer comprising a primary aromatic amino silver halide developing agent and l-carboxymethyl-Z- methylpyridinium bromide.

18. color forming photographic developer comprising a primary aromatic amino silver halide developing agent and l-(carbethoxymethyl) -2-methylpyridinium thiocyanate.

LAWRENCE G. WELLIVER. CARL E. JOHNSON.

Name Date Trivelli et al May 6, 1947 Number 

1. AN ALKALINE PHOTOGRAPHIC DEVELOPER FOR SILVER HALIDE EMULSIONS COMPRISING AN AROMATIC SILVER HALIDE DEVELOPING AGENT AND A PYRIDINUM SALT SELECTED FROM THE CLASS CONSISTING OF THOSE CORRESPONDING TO THE FOLLOWING GENERAL FORMULA: 